Concentric Two-Speed Focusing Mechanism With Single Rotary Control
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Solution Overview
Problem
Conventional two-speed focusing mechanisms require separate controls for coarse and fine focus adjustments, necessitating additional packaging space due to the radial configuration of spur gears, which is undesirable for compact designs.
Innovation Solution
A two-speed focusing mechanism that translates a single rotary motion into axial displacement of a lens at two different speeds using concentric tubular members with varying helical grooves and bearings, allowing for compact packaging within a lens housing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single rotary mechanism is used for two-speed focusing, then device complexity is reduced and packaging space is optimized, but it becomes challenging to achieve both coarse and fine focus adjustments with varying speeds from a single rotary motion
Solution Approach 1:
The patent employs nested tubular members where the first drive (coarse focus) and second drive (fine focus) are concentrically arranged. The second drive is positioned inside the first drive, allowing both mechanisms to share the same rotational axis and packaging space. This nesting arrangement enables dual-speed focusing functionality while minimizing the overall device footprint and eliminating the need for separate controls.
Solution Approach 2:
The patent utilizes helical grooves with different pitches on the nested drives to dynamically switch between coarse and fine focus speeds. The first drive has a larger pitch for coarse adjustments, while the second drive has a smaller pitch for fine adjustments. As the rotary mechanism rotates, the bearing engages with different groove pitches at different rotational positions, automatically providing the appropriate focus speed without requiring separate controls.
2Volume of stationary object
If concentric tubular members with varying helical grooves are used, then packaging space is optimized, but manufacturing precision requirements increase
Solution Approach 1:
The patent divides the focusing mechanism into segmented functional components: the first drive with its helical groove for coarse focus, the second drive with its helical groove for fine focus, and bearings that engage with these grooves. Each component can be manufactured and assembled separately, allowing for quality control and precision verification at each stage. The segmentation also enables the use of standard manufacturing tolerances for each component rather than requiring ultra-precise monolithic manufacturing.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Enables quick coarse focus adjustment followed by precise fine focus adjustment using a single rotary mechanism, optimizing space utilization and user convenience.
Implementation Method 1
The first groove is helical and has a first pitch and an outer surface of the first drive. The second groove being helical and having a second pitch that is less than the first pitch. A rotation of the second drive translates the carrier axially at different speeds.
Data Source
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AI summary
A two-speed focusing mechanism includes a base having an inner guide, a carrier disposed within the inner guide, a first drive, an outer guide and a second drive. A first and second bearing are disposed in a respective inner dimple of the carrier and a second bearing is disposed within a first dimple of the first drive. The first and second bearings are held within a respective inner slot and outer slot and a first guide and second guide, wherein a rotation of the second drive is translated into an axial movement of the carrier at different speeds.